Sheet discharging apparatus, image reading apparatus, and image forming apparatus

ABSTRACT

A sheet discharging apparatus includes a discharge unit, a stacking portion and a swing guide. The stacking portion includes an upstream supporting portion, a wall surface portion, a first supporting portion provided downstream of the upstream supporting portion and including a first inclined surface, and a second supporting portion provided downstream of the upstream supporting portion and including a second inclined surface. The swing guide overlaps with the first supporting portion as viewed in a width direction of a sheet in a case where the swing guide is not in contact with a sheet discharged by the discharge unit, and swings upward in a case where the swing guide is pushed by a sheet.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a sheet discharging apparatus thatdischarges a sheet, an image reading apparatus that reads imageinformation from a sheet, and an image forming apparatus that forms animage on a sheet.

Description of the Related Art

An image reading apparatus incorporated in an image forming apparatussuch as a copier or a multifunctional apparatus includes an autodocument feeder (ADF) that automatically feeds one sheet at a timeserving as a document. A sheet fed by the ADF is supported on adischarge tray after image information thereof is read by an imagesensor.

In recent years, there has been a demand for automatically feedingsheets of various sizes by an ADF and reading image information.According to this, there has been a demand that sheets stacked on adischarge tray are precisely aligned also in the case of feeding sheetsof different kinds having different lengths in a conveyance direction bythe ADF. Japanese Patent Laid-Open No. 2018-64156 discloses aconfiguration in which an inclined surface inclined such that a moredownstream portion thereof in a sheet discharge direction extends moreupward is provided on a discharge tray.

However, it is sometimes difficult to maintain good alignment of sheetsof a plurality of sizes even in the case where the inclined surfacedescribed in the document above is provided.

SUMMARY OF THE INVENTION

The present invention provides a sheet discharging apparatus, an imagereading apparatus and an image forming apparatus that can achieve goodalignment of sheets of various sizes.

According to one aspect of the invention, a sheet discharging apparatusincludes: a discharge unit configured to discharge a sheet in adischarge direction; a stacking portion on which sheets discharged bythe discharge unit are stacked; and a swing guide configured to swingabout a swing shaft positioned above the stacking portion. The stackingportion includes: an upstream supporting portion configured to support asheet discharged from the discharge unit; a wall surface portionerecting upward from an upstream end of the upstream supporting portionin the discharge direction; a first supporting portion provideddownstream of the upstream supporting portion in the discharge directionand including a first inclined surface inclined upward toward adownstream side in the discharge direction; and a second supportingportion provided downstream of the upstream supporting portion in thedischarge direction and including a second inclined surface inclinedupward toward the downstream side in the discharge direction. The swingguide is configured to overlap with the first supporting portion asviewed in a width direction of a sheet perpendicular to the dischargedirection in a case where the swing guide is not in contact with a sheetdischarged by the discharge unit, and swing upward in a case where theswing guide is pushed by a sheet. As viewed in the width direction, thestacking portion is configured to satisfy L1<L2, L4<L2, H1<H2, andH4<H2, where L1 represents a distance from a first intersection point toa first vertex in a horizontal direction, the first intersection pointbeing an intersection point where the wall surface portion and theupstream supporting portion intersect, the first vertex being a highestpoint of the first inclined surface in a gravity direction, H1represents a distance from the first intersection point to the firstvertex in the gravity direction, L2 represents a distance from the firstintersection point to a second vertex in a horizontal direction, thesecond vertex being a highest point of the second inclined surface inthe gravity direction, H2 represents a distance from the firstintersection point to the second vertex in the gravity direction, L4represents a distance from the first intersection point to a secondintersection point in the horizontal direction, the second intersectionpoint being an intersection point where the swing guide and the firstinclined surface of the first supporting portion intersect, and H4represents a distance from the first intersection point to the secondintersection point in the gravity direction.

According to another aspect of the invention, a sheet dischargingapparatus includes: a discharge unit configured to discharge a sheet ina discharge direction; a swing guide configured to swing about a swingshaft; an upstream supporting portion configured to support a sheetdischarged from the discharge unit; a wall surface portion erectingupward from an upstream end of the upstream supporting portion in thedischarge direction; a first supporting portion provided downstream ofthe upstream supporting portion in the discharge direction and includinga first inclined surface inclined upward toward a downstream side in thedischarge direction; and a second supporting portion provided downstreamof the upstream supporting portion in the discharge direction andincluding a second inclined surface inclined upward toward thedownstream side in the discharge direction. The swing guide overlapswith the first inclined surface of the first supporting portion asviewed in a width direction of a sheet perpendicular to the dischargedirection in a case where the swing guide is not in contact with a sheetdischarged by the discharge unit. The swing guide swings upward in acase where the swing guide is pushed by a sheet. A highest point of thesecond inclined surface is downstream of a highest point of the firstinclined surface in the discharge direction. The highest point of thesecond inclined surface is higher than the highest point of the firstinclined surface.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a discharge tray of an ADF according toan exemplary embodiment.

FIG. 2 is a diagram schematically illustrating an image formingapparatus according to the exemplary embodiment.

FIG. 3 is a diagram schematically illustrating an image readingapparatus according to the exemplary embodiment.

FIG. 4 is a section view of the image reading apparatus according to theexemplary embodiment.

FIG. 5 is a section view of a discharge tray according to the exemplaryembodiment.

FIG. 6 is a section view of the discharge tray according to theexemplary embodiment.

FIG. 7 is a section view of the discharge tray according to theexemplary embodiment.

FIG. 8 is a section view of the discharge tray and a swing guideaccording to the exemplary embodiment.

FIG. 9 is a section view of the discharge tray of the exemplaryembodiment illustrating a state in which a document of a first size issupported on the discharge tray.

FIG. 10 is a section view of the discharge tray of the exemplaryembodiment illustrating a state in which a document of a second size issupported on the discharge tray.

FIG. 11 is a section view of the discharge tray of the exemplaryembodiment illustrating a state in which a document of a third size issupported on the discharge tray.

DESCRIPTION OF THE EMBODIMENTS

An exemplary embodiment of the present invention will be described belowwith reference to drawings.

FIG. 1 is a perspective view of an ADF 300 according to an exemplaryembodiment of the present disclosure. To be noted, in FIG. 1,illustration of a feed tray is omitted such that a discharge tray 303 isvisible. FIG. 2 is a schematic view of an image forming apparatus 200including an image reading apparatus 201. FIG. 3 is a schematic view ofthe ADF 300 and a reader portion 301 constituting the image readingapparatus 201. FIG. 4 is a diagram illustrating a sectionalconfiguration of the image reading apparatus 201.

Image Forming Apparatus

First, a schematic configuration of the image forming apparatus 200 ofan electrophotographic system including the image reading apparatus 201will be described with reference to FIG. 2. To be noted, the imageforming apparatus 200 is merely an example of an image formingapparatus, and examples of image forming apparatus to which thetechnique of the present disclosure is applicable include facsimileapparatuses and multifunctional apparatuses including the image readingapparatus 201. In addition, an image forming unit incorporated in theimage forming apparatus is not limited to an electrophotographic system,and the image forming apparatus may include, for example, a printingunit of an inkjet system.

As illustrated in FIG. 2, the image forming apparatus 200 includes animage forming apparatus body 202 and the image reading apparatus 201mounted on an upper portion of the image forming apparatus body 202. Theimage forming apparatus body 202 includes an image forming portion 3serving as an image forming unit disposed approximately at the centerthereof, and a feeding unit for feeding a recording material S includingfeed cassettes 6 is positioned below the image forming portion 3. As therecording material S, a wide variety of sheets of different sizes andmaterials such as paper sheets like regular paper sheets and cardboards,plastic films, cloths, surface-treated sheet materials such as coatedpaper, and sheet materials having irregular shapes such as envelopes andindex sheets can be used. The image reading apparatus 201 includingimage sensors 409 and 410 serving as image reading units for reading animage of a document is provided above the image forming apparatus body202.

In the image forming apparatus body 202, the image forming portion 3 isconfigured as a print engine of an electrophotographic system. The imageforming portion 3 of the present exemplary embodiment is configured as atandem-type intermediate transfer system, and includes four imageforming units 10Y, 10M, 10C, and 10K and an intermediate transfer belt23 serving as an intermediate transfer member.

The image forming unit 10Y forms a yellow toner image by anelectrophotographic process. That is, a photosensitive drum 11 servingas a photosensitive member rotates, and a charging device 12 uniformlycharges the surface of the photosensitive drum 11. A laser scanner 13irradiates the photosensitive drum 11 with laser light modulated on thebasis of image information, and thus draws an electrostatic latent imageon the surface of the photosensitive drum 11. A developing unit 14supplies charged toner particles to the photosensitive drum 11, and thusdevelops the electrostatic latent image on the surface of thephotosensitive drum 11 into a toner image. This toner image istransferred onto the intermediate transfer belt 23 through primarytransfer by a primary transfer roller 15. Attached matter such astransfer residual toner remaining on the photosensitive drum 11 withoutbeing transferred onto the intermediate transfer belt 23 is removed by adrum cleaner 16. The process described above is performed in parallel byeach of the image forming units 10Y to 10K, and toner images ofrespective colors of yellow, magenta, cyan, and black are formed.

The intermediate transfer belt 23 is rolled around a plurality ofrollers including a secondary transfer inner roller 18, and isrotationally driven in a direction following a rotation direction ofphotosensitive drums 11, that is, a clockwise direction in FIG. 2. Tonerimages of respective colors formed by the image forming units 10Y to 10Kare transferred through primary transfer so as to be superimposed on oneanother, and thus a full-color toner image is formed on the intermediatetransfer belt 23. This toner image is conveyed to a secondary transferportion formed between the secondary transfer inner roller 18 and asecondary transfer roller 19 opposed thereto by the rotation of theintermediate transfer belt 23.

The image forming apparatus 200 includes a cassette feeding portion 4and a manual feeding portion 5 as sheet feeding apparatuses for feedingthe recording material S. The cassette feeding portion 4 includes theplurality of feed cassettes 6, and the feeding unit 7 feeds therecording material S one by one from one of the feed cassettes 6 towarda registration roller 17. In addition, the manual feeding portion 5provided on a side portion of the apparatus body 202 feeds the recordingmaterial S one by one by a feeding unit 8 toward the registration roller17. The feeding units 7 and 8 each include a feeding member such as afeed roller that delivers out the recording material S from a feedcassette 6 or a manual feed tray, and a separation member such as aseparation roller or a separation pad that applies a frictional force toa sheet of the recording material S superimposed on another sheet of therecording material S conveyed by the feeding member to prevent multiplesheets of the recording material S from being conveyed simultaneously.

The registration roller 17 delivers the recording material S into thesecondary transfer portion in synchronization with the formation of thetoner image by the image forming portion 3. The recording material S onwhich the toner image has been transferred from the intermediatetransfer belt 23 through secondary transfer in the secondary transferportion is conveyed to a fixing unit 21. The fixing unit 21 applies heatand pressure to the toner image on the recording material S whilenipping and conveying the recording material S, and thus fixes the tonerimage to the recording material S. In the case of duplex printing, therecording material S having passed through the fixing unit 21 is guidedto a reverse conveyance path 26, switched back, and conveyed to theimage forming portion 3 in a state in which a first surface and a secondsurface thereof are reversed, and an image is formed on the secondsurface of the recording material S. In the case of simplex printing andin the case where image formation on the second surface in the duplexprinting is finished, the recording material S having passed through thefixing unit 21 is discharged from the apparatus body 202 by a dischargeroller 25.

To be noted, FIG. 2 illustrates a configuration in which the recordingmaterial S on which an image has been formed is discharged onto adischarge tray disposed on a side surface of the image forming apparatusbody 202 or onto a sheet processing apparatus connected to the imageforming apparatus body 202. Instead of this, a so-called in-bodydischarge configuration in which a space is provided between the imagereading apparatus 201 and the image forming apparatus body 202 in thegravity direction to form a body discharge portion onto which arecording material having undergone image formation in the image formingapparatus body 202 is discharged may be employed.

Image Reading Apparatus

Next, a schematic configuration of the ADF 300 and the reader portion301 constituting the image reading apparatus 201 will be described withreference to FIG. 3.

As illustrated in FIG. 3, the image reading apparatus 201 includes theADF 300 that feeds a plurality of documents one by one by separating onedocument from another for reading an image on the document by an imagesensor while conveying the document. As the document, a wide variety ofsheets of different sizes and materials such as paper sheets likeregular paper sheets and cardboards, plastic films, cloths, sheetmaterials whose surface is treated such as coated paper, and sheetmaterials having irregular shapes such as envelopes and index sheets canbe used. In particular, in the present exemplary embodiment, sheets of asmall size that are conventionally hardly handled by an ADF, forexample, business cards, can be conveyed by the ADF 300.

The ADF 300 includes a feed tray 302 on which documents are placed, anda discharge tray 303 serving as a stacking portion onto which documentswhose images have been read are discharged and on which the dischargeddocuments are stacked. The reader portion 301 for reading an image of adocument conveyed by the ADF 300 or an image of a still document, forexample, a thick document such as a book, is provided below the ADF 300.

In the description below, as illustrated in FIG. 3, the left-rightdirection of the image reading apparatus 201 as viewed from a user, thatis, as viewed from the front side of the image forming apparatus 200,will be referred to as an X direction. The front-rear direction of theimage reading apparatus 201 perpendicular to the X direction, that is,the main scanning direction or width direction of documents, will bereferred to as a Y direction. In addition, the up-down direction of theimage reading apparatus 201 perpendicular to both of the X direction andthe Y direction, that is, the gravity direction in normal use, will bereferred to as a Z direction. The ADF 300 feeds a document placed on thefeed tray 302 toward one side in the X direction, and discharges thedocument toward the other side in the X direction, that is, in a sheetdischarge direction of the present exemplary embodiment, onto thedischarge tray 303.

Next, the inner structure of the image reading apparatus 201 will bedescribed with reference to FIG. 4, which is a section view of the imagereading apparatus 201 as viewed in the Y direction. The ADF 300 includesa pickup roller 401, a separation roller pair 402, and a plurality ofroller pairs 403 to 406 as a plurality of conveyance units that convey asheet. The pickup roller 401 abuts the uppermost document amongdocuments 400 placed on the feed tray 302, and sends out the uppermostdocument toward the separation roller pair 402. The separation rollerpair 402 separates one document 400 from a plurality of documents 400when a plurality of documents 400 are received from the pickup roller401, and conveys the separated document 400.

The plurality of conveyance roller pairs convey the document 400 througha reading position while passing the document 400 onto one another. Inthis case, the reading position is a position where the image sensors409 and 410 scan the document 400. Among these conveyance roller pairs,a pulling roller pair 403 conveys the document 400 while pulling out thedocument 400 from the separation roller pair 402. A first reading rollerpair 404 and a second reading roller pair 405 convey the document 400such that the document 400 passes through the reading position whilestabilizing the position of the document 400 at the reading position soas to improve the reading precision. A discharge roller pair 406receives the document 400 having passed through the reading position anddischarges the document 400 onto the discharge tray 303.

A swing guide 411 is swingably supported on a lower portion of the feedtray 302 disposed above the discharge tray 303. The swing guide 411 hasa function of applying a resistance force to the document 400 dischargedby the discharge roller pair 406 to restrict excessive movement of thedocument 400 in the discharge direction, which is rightward in FIG. 4.To be noted, the swing guide 411 may be urged downward by the weightthereof, or may be, for example, urged downward by a spring memberattached to a swing shaft 801.

The image sensor 409 serving as a first reading unit is provided in thereader portion 301. When reading an image from a first surface of thedocument 400 conveyed by the ADF 300, the image sensor 409 stops at aposition where the image sensor 409 opposes a document feeding-readingglass 407, that is, at a position illustrated in FIG. 4. When reading animage from a still document placed on a platen glass 408, the imagesensor 409 reads the image while moving on a rail provided in the readerportion 301 in the X direction, which is a sub-scanning direction.

Further, an image sensor 410 serving as a second reading unit isprovided in the ADF 300 at a position opposing the image sensor 409 ofthe reader portion 301. Therefore, images on both surfaces of thedocument 400 conveyed by the ADF 300 can be simultaneously read by usingthe two image sensors 409 and 410. To be noted, as the image sensors 409and 410, a contact image sensor: CIS, which is a module of an imagesensor such as a complementary metal oxide semiconductor: CMOS and anequal-magnification optical system, and a CCD-type image sensor in whicha charge-coupled device: CCD and a reduced optical system are combinedcan be both used.

As described above, the ADF 300 serving as a sheet discharging apparatusof the present exemplary embodiment has a function of discharging adocument whose image has been read onto the discharge tray 303 by thedischarge roller pair 406 serving as a discharge unit.

Discharge Tray

Next, a schematic configuration of the discharge tray 303 will bedescribed with reference to FIGS. 1 to 4. The discharge tray 303includes a wall surface portion 100, an upstream supporting surface 101,a first projection 102, second projections 103, and third projections104.

The wall surface portion 100 is erected, i.e., extends upward in the Zdirection, from an upstream end of the discharge tray 303 in thedischarge direction. The upstream supporting surface 101 serving as anupstream supporting portion of the present exemplary embodiment extendsdownstream with respect to the wall surface portion 100 in the dischargedirection of documents by the discharge roller pair 406, that is, in theX direction.

The first projection 102 serving as a first supporting portion of thepresent exemplary embodiment is provided downstream of the upstreamsupporting surface 101 in the discharge direction, and projects upwardin the Z direction with respect to the upstream supporting surface 101.The single first projection 102 is provided at an approximately centerposition of the discharge tray 303 in the Y direction.

The second projections 103 serving as second supporting portions of thepresent exemplary embodiment are disposed such that the first projection102 is interposed therebetween in the Y direction, and have shapesprojecting upward in the Z direction as viewed in the Y direction. Thethird projections 104 serving as third supporting portions of thepresent exemplary embodiment are also disposed such that the firstprojection 102 is interposed therebetween in the Y direction, and haveshapes projecting upward in the Z direction as viewed in the Ydirection.

The second projection 103 and the third projection 104 on one side(front side of the image reading apparatus) in the Y direction areconnected in the X direction to make up a rib-like projection on theupper surface of the discharge tray 303. Similarly, the secondprojection 103 and the third projection 104 on the other side (rear sideof the image reading apparatus) in the Y direction are also connected inthe X direction to make up a rib-like projection on the upper surface ofthe discharge tray 303.

The arrangement of the first supporting portion, the second supportingportions, and the third supporting portions in the Y direction can beappropriately modified. For example, a plurality of first projections102 may be provided at a plurality of positions in the Y direction. Inaddition, two second projections 103 and/or two third projections 104may be disposed on each side of the center position of the dischargetray 303 in the Y direction, that is, four second projections 103 and/orfour third projections 104 may be provided in total.

The swing guide 411 is provided at a position corresponding to the firstprojection 102 in the X direction and the Y direction in a space betweenthe feed tray 302 and the discharge tray 303. The swing guide 411 issupported by a bearing portion 302 a of the feed tray 302 positionedabove the discharge tray 303 so as to be swingable about the swing shaft801 extending in the Y direction. Distal end portions 412 of the swingguide 411 on the side farther from the swing shaft 801 have a shapebranched into two portions in the Y direction, and are disposed suchthat the first projection 102 is interposed between one branch to afirst side in the Y direction and the other branch to a second side inthe Y direction of the branched shape. Therefore, in a state in which adocument is not discharged onto the discharge tray 303 and the swingguide 411 dangles due to its own weight, the distal end portions of theswing guide 411 overlap with the first projection 102 as viewed in the Ydirection as illustrated in FIGS. 1 and 4. In addition, the distal endportions 412 of the swing guide 411 are respectively positioned betweenthe first projection 102 and the second projection 103 on the one side(first side) in the Y direction, i.e., a first projected portion of thesecond supporting portion, and between the first projection 102 and thesecond projection 103 on the other side (second side) in the Ydirection, i.e., a second projected portion of the second supportingportion.

To be noted, although only one first projection 102 and one swing guide411 are provided in the present exemplary embodiment, a plurality offirst projections 102 and/or a plurality of swing guides 411 may beprovided at a plurality of positions in the Y direction. In this case,the number of the first projections 102 and the number of the swingguides 411 do not have to be equal, and for example, the number of theswing guides 411 may be smaller than the number of the first projections102.

Shape of Discharge Tray and Position of Swing Guide

Shapes of projections 102, 103, and 104 corresponding to the firstsupporting portion, second supporting portions, and third supportingportions of the present exemplary embodiment will be described in detailbelow with reference to FIGS. 5 to 7.

First, positions of points and the like for specifying the shape of thefirst projection 102 as viewed in the Y direction are defined as followswith reference to FIG. 5.

A point where the wall surface portion 100 and the upstream supportingsurface 101 intersect is defined as a first intersection point 500.

A surface constituting an upstream surface of the first projection 102in the discharge direction of documents and inclined upward toward thedownstream side in the discharge direction is defined as a firstinclined surface 501.

The highest point of the first inclined surface 501 in the Z direction,that is, a downstream end of the first inclined surface 501 in thedischarge direction, is defined as a first vertex 502.

A point where the first inclined surface 501 and the upstream supportingsurface 101 intersect is defined as a third intersection point 503.

A straight line connecting the third intersection point 503 and thefirst vertex 502 is defined as a first straight line Ln1.

A distance from the first intersection point 500 to the first vertex 502in the X direction is defined as L1 [mm].

A distance from the first intersection point 500 to the first vertex 502in the Z direction is defined as H1 [mm].

An angle of the first straight line Ln1 with respect to the X directionis defined as θ1 [deg].

Here, in the case where the upstream surface and the downstream surfaceof the first projection 102 do not intersect with each other with anangle therebetween but are smoothly connected to each other via a curvedsurface, the first intersection point 500, the third intersection point503, and the first vertex 502 are virtual points where extension linesof the upstream surface and the downstream surface intersect. This alsoapplies to points for specifying the shapes of the second projections103 and the third projections 104 that will be described below.

In addition, in the present exemplary embodiment, since the firstinclined surface 501 is constituted by a single flat surface, the firstinclined surface 501 coincides with the first straight line Ln1.However, it should be noted that, in the case where the first inclinedsurface 501 is a curved surface or made up of a combination of aplurality of flat surfaces, the first inclined surface 501 does notcoincide with the first straight line Ln1. This also applies to secondinclined surfaces 600 of the second projections 103 and second straightlines Ln2 that will be described later.

Positions of points and the like for specifying the shape of each of thesecond projections 103 as viewed in the Y direction are defined asfollows with reference to FIG. 6.

A surface constituting an upstream surface of the second projection 103in the discharge direction of documents and inclined upward toward thedownstream side in the discharge direction is defined as a secondinclined surface 600.

The highest point of the second inclined surface 600, that is, adownstream end of the second inclined surface 600 in the dischargedirection, is defined as a second vertex 601.

A point where the second inclined surface 600 and the upstreamsupporting surface 101 intersect is defined as a fourth intersectionpoint 602.

A straight line connecting the fourth intersection point 602 and thesecond vertex 601 is defined as a second straight line Ln2.

A distance from the first intersection point 500 to the second vertex601 in the X direction is defined as L2 [mm].

A distance from the first intersection point 500 to the second vertex601 in the Z direction is defined as H2 [mm].

An angle of the second straight line Ln2 with respect to the X directionis defined as θ2 [deg].

As described above, these intersection points and highest points may bevirtual points. In addition, in the present exemplary embodiment,although the second inclined surface 600 coincides with the secondstraight line Ln2 because the second inclined surface 600 is a singleflat surface, the second inclined surface 600 may be a curved surface ora combination of a plurality of flat surfaces, and in this case, thesecond inclined surface 600 does not coincide with the second straightline Ln2.

Positions of points and the like for specifying the shape of each of thethird projections 104 as viewed in the Y direction are defined asfollows with reference to FIG. 7.

A surface constituting an upstream surface of the third projection 104in the discharge direction of documents and inclined upward toward thedownstream side in the discharge direction is defined as a thirdinclined surface 700.

The highest point of the third inclined surface 700, that is, adownstream end of the third inclined surface 700 in the dischargedirection, is defined as a third vertex 701.

A distance from the first intersection point 500 to the third vertex 701in the X direction is defined as L3 [mm].

A distance from the first intersection point 500 to the third vertex 701in the Z direction is defined as H3 [mm].

As described above, these intersection points and highest points may bevirtual points.

Next, the position of the swing guide 411 will be described withreference to FIG. 8. FIG. 8 illustrates a state in which the swing guide411 is not pushed by a document discharged onto the discharge tray 303.That is, the swing guide 411 is positioned at a lower limit position ina movable range thereof in a swing direction 802 about the swing shaft801. In this state, the distal end portions of the swing guide 411overlap with the first projection 102 as viewed in the Y direction. Morespecifically, an upstream surface of the swing guide 411 in thedischarge direction intersects with the first inclined surface 501,which is an upstream surface of the first projection 102 in thedischarge direction.

Positions of points and the like for specifying the shape of the swingguide 411 as viewed in the Y direction are defined as follows.

A point where the first inclined surface 501 and the swing guide 411intersect is defined as a second intersection point 800.

A distance from the first intersection point 500 to the secondintersection point 800 in the X direction is defined as L4 [mm].

A distance from the first intersection point 500 to the secondintersection point 800 in the Z direction is defined as H4 [mm].

Further, the shape of the discharge tray 303 according to the presentexemplary embodiment is configured such that the values L1 to L4, H1 toH4, θ1, and θ2 related to the first projection 102, the secondprojections 103, the third projections 104, and the swing guide 411satisfy the following relationships.L1<L2<L3  (1)L4<L2  (2)H1<H2<H3  (3)H4<H2  (4)

Relationship (1) indicates that the first vertex 502 of the firstprojection 102, the second vertices 601 of the second projections 103,and the third vertices 701 of the third projections 104 are arranged inthis order from the upstream side to the downstream side in thedischarge direction of documents. Relationship (3) indicates that thefirst vertex 502 of the first projection 102, the second vertices 601 ofthe second projections 103, and the third vertices 701 of the thirdprojections 104 are arranged in this order from the lower side to thehigher side in the gravity direction.

Relationship (2) indicates that the second intersection point 800 wherethe swing guide 411 and the first inclined surface 501 intersect ispositioned upstream of the second vertices 601 of the second projections103 in the discharge direction. Relationship (4) indicates that thesecond intersection point 800 is positioned lower than the secondvertices 601 of the second projections 103 in the gravity direction. Asdescribed above, since L4<L2 and H4<H2 are satisfied, the dischargespace above the discharge tray 303 is blocked by the swing guide 411 ina state in which the swing guide 411 is not pushed up by a document asillustrated in FIG. 8. In other words, the downstream side in thedischarge direction of the space defined between the discharge tray 303and the feed tray 302 in the gravity direction as viewed in the Ydirection is closed by the first inclined surface 501 of the firstprojection 102 and the swing guide 411.

Length of Document in Conveyance Direction and Dimensions of DischargeTray

The ADF 300 of the present exemplary embodiment is configured to becapable of handling at least three document sizes having differentlengths in the conveyance direction. In the description below, amongrepresentative document sizes that can be handled by the ADF 300, a sizehaving a small length in the conveyance direction will be referred to asa first size, a size having a medium length in the conveyance directionwill be referred to as a second size, and a size having a large lengthin the conveyance direction will be referred to as a third size. Forexample, the first size is A6R having a length of 148 mm in theconveyance direction and a width of 105 mm. For example, the second sizeis A5R having a length of 210 mm in the conveyance direction and a widthof 148 mm. For example, the third size is A4R having a length of 297 mmin the conveyance direction and a width of 210 mm. To be noted, A6R,A5R, A4R are merely examples, and may be changed to document sizesassumed to be frequently used.

(A) Arrangement of Document of First Size and First Projection

The first projection 102 of the discharge tray 303 is provided at aposition corresponding to a document of the first size. That is, thefirst projection 102 is disposed so as to come into contact with aleading end of a document in the discharge direction on the firstinclined surface 501 in a state in which a trailing end of the documenthas been released from the discharge roller pair 406 in the case where adocument of the first size is discharged. In the case where A6R isassumed as the first size, the first vertex 502 of the first projection102 is preferably disposed such that L1 [mm] and H1 [mm] satisfy148≤L1<180 and 20≤H1<40.

In addition, the swing guide 411 is disposed such that a space in whichdocuments of the first size can be stacked is secured on the upstreamside in the discharge direction in a state in which the swing guide 411is not pushed up and overlaps with the first projection 102 as viewed inthe Y direction. For example, the swing guide 411 is preferably disposedsuch that L4 [mm] and H4 [mm] defining the position of the secondintersection point 800 satisfy L1=L4 and H1=H4. To be noted, in the casewhere A6R is assumed as the first size, even if L4 or H4 is not equal toL1 or H1, the swing guide 411 is preferably disposed such that148≤L4<180 and 20≤H4<40 are satisfied.

In the case where the first projection 102 and the swing guide 411 aredisposed as described above, the position of a first-size document 900discharged onto the discharge tray 303 is regulated by the firstinclined surface 501 of the first projection 102 and the swing guide 411as illustrated in FIG. 9. That is, the first-size document 900 comesinto contact with the first inclined surface 501 or the swing guide 411on a leading end thereof in a state in which a trailing end thereof inthe discharge tray has been released from the discharge roller pair 406.At this time, the swing guide 411 resists an inertia force 901 of thedocument 900 and basically does not swing to a position above the firstprojection 102 even when the swing guide 411 comes into contact with thedocument 900 not nipped by the discharge roller pair 406. Therefore,downstream movement of the first-size document 900 beyond the secondintersection point 800 in the discharge direction is hindered by theswing guide 411 and the first projection 102. As a result, thefirst-size document 900 is supported on the upstream supporting surface101 and the first inclined surface 501 in a state in which the positionthereof in the discharge direction is regulated within a region upstreamof the second intersection point 800 in the discharge direction asindicated by a broken line 902 in FIG. 9, and therefore good alignmentcan be achieved.

(B) Document of Second Size and Arrangement of Second Projections

The second projections 103 are provided at positions corresponding to adocument of the second size. That is, the second projections 103 aredisposed at such positions that a leading end portion of the document ofthe second size in the discharge direction can be supported by thesecond inclined surfaces 600. In other words, the second projections 103are disposed such that at least part of the second inclined surfaces 600faces a lower surface of the document as viewed in the Y direction in astate in which a trailing end of the document of the second sizedischarged onto the discharge tray 303 is abutting the wall surfaceportion 100 as illustrated in FIG. 10. In the case where A5R is assumedas the second size, the second vertices 601 of the second projections103 are preferably disposed such that L2 [mm] and H2 [mm] satisfy180≤L2<240 and 40≤H2<60.

In the case where the second projections 103 are disposed as describedabove, the position of a second-size document 1000 disposed onto thedischarge tray 303 is regulated by the combination of the swing guide411, the first projection 102, and the second projections 103 asillustrated in FIG. 10. That is, the second-size document 1000 isdischarged while pushing up the swing guide 411 in a state of beingnipped by the discharge roller pair 406, and the leading end portionthereof moves in contact with the second inclined surfaces 600 of thesecond projections 103. The second vertices 601 of the secondprojections 103 are positioned downstream of the first vertex 502 of thefirst projection 102 in the discharge direction and higher than thefirst vertex 502 in the gravity direction, and therefore the document1000 forms an inclined surface shape connecting the first vertex 502 andthe second vertices 601.

Here, in a state before the first document 1000 is discharged, the spaceabove the discharge tray 303 is blocked by the first projection 102 andthe swing guide 411. Therefore, the first document 1000 is conveyedwhile pushing up the swing guide 411 and receiving a frictional dragfrom the swing guide 411 and the first projection 102. Therefore, evenin the case where the conveyance speed of the document 1000 by thedischarge roller pair 406 is higher than 340 mm/s, movement of thedocument 1000 to a position far away from the wall surface portion 100by an inertia force can be suppressed.

In the case of discharging the second and subsequent documents 1000,since the swing guide 411 has already swung to a position higher thanthe first projection 102, the influence of the frictional force from theswing guide 411 and the first projection 102 is relatively smaller.Meanwhile, the document 1000 being discharged does not move to aposition far away from the wall surface portion 100 because the document1000 is discharged while being pushed up along the inclined surfaceshape formed by the already-discharged document 1000. As describedabove, the position of the second-size document 1000 in the dischargedirection is regulated by the swing guide 411, the first projection 102,and the second projections 103 regardless of in which ordinal number thedocument 1000 is discharged, and therefore good alignment is achieved.

To be noted, the angle θ2 formed between the second straight line Ln2and the horizontal direction is preferably smaller than the angle θ1formed between the first straight line Ln1 and the horizontal direction,that is, θ2<θ1 is preferably satisfied. As a result of this, thereaction force that the document 1000 receives when the leading end ofthe document 1000 comes into contact with the second inclined surfaces600 projecting to a higher position than the first vertex 502 of thefirst projection 102 can be attenuated, and thus troubles such asbending or stacking failure of the document 1000 caused as a result ofthe document 1000 being caught can be suppressed.

Examples of preferable numerical ranges of the angle θ1° formed betweenthe first straight line Ln1 and the horizontal direction and the angleθ2° formed between the second straight line Ln2 and the horizontaldirection are 40≤θ1≤55, 25≤θ2≤40, and θ1−θ2≥5. When 25≤θ2≤40 and θ1−θ2≥5are satisfied, the document 1000 being caught by the second inclinedsurfaces 600 can be effectively suppressed. In addition, when 40≤θ1≤55is satisfied, the effect of the first inclined surface 501 regulatingthe position of the first-size document 900 as described in (A) abovecan be enhanced.

(C) Document of Third Size and Arrangement of Third Projections

The third projections 104 are provided at positions corresponding to adocument of a third size. That is, the third projections 104 aredisposed at such positions that the third inclined surfaces 700 cansupport a leading end portion of a document of the third size in thedischarge direction. In the case where A4R is assumed as the third size,the third vertices 701 of the third projections 104 are preferablydisposed such that L3 [mm] and H3 [mm] satisfy 240≤L3<360 and 60≤H3<80.

In the case where the third projections 104 are disposed as describedabove, the position of a third-size document 1100 discharged onto thedischarge tray 303 is regulated by the cooperation of the swing guide411, the first projection 102, the second projections 103, and the thirdprojections 104 as illustrated in FIG. 11. That is, the third-sizedocument 1100 is discharged while pushing up the swing guide 411 in astate of being nipped by the discharge roller pair 406, and the leadingend portion thereof comes into contact with the second inclined surfaces600 and then moves in contact with the third inclined surfaces 700.Then, a lower surface of the document 1100 is supported by the firstvertex 502 of the first projection 102, the second vertices 601 of thesecond projections 103, and the third vertices 701 of the thirdprojections 104. Since the third vertices 701 are positioned downstreamof the second vertices 601 in the discharge direction and higher thanthe second vertices 601 in the gravity direction, the document 1100forms an inclined surface shape smoothly connecting the first vertex502, the second vertices 601, and the third vertices 701.

Here, in a state before the first document 1100 is discharged, the spaceabove the discharge tray 303 is blocked by the first projection 102 andthe swing guide 411. Therefore, the first document 1100 is conveyedwhile pushing up the swing guide 411 and receiving a frictional dragfrom the swing guide 411 and the first projection 102. Therefore, evenin the case where the conveyance speed of the document 1100 by thedischarge roller pair 406 is higher than 340 mm/s, movement of thedocument 1100 to a position far away from the wall surface portion 100by an inertia force can be suppressed.

In the case of discharging the second and subsequent documents 1100,since the swing guide 411 has already swung to a position higher thanthe first projection 102, the influence of the frictional force from theswing guide 411 and the first projection 102 is relatively smaller.Meanwhile, the document 1100 being discharged does not move to aposition far away from the wall surface portion 100 because the document1100 is discharged while being pushed up along the inclined surfaceshape formed by the already-discharged document 1100. As describedabove, the position of the third-size document 1100 in the dischargedirection is regulated by the swing guide 411, the first projection 102,the second projections 103, and the third projections 104 regardless ofin which ordinal number the document 1100 is discharged, and thereforegood alignment is achieved.

As described above, the discharge tray 303 of the present exemplaryembodiment is configured such that L1<L2, L4<L2, H1<H2, and H4<H2 aresatisfied for the swing guide 411, the first projection 102, and thesecond projections 103. As a result of this, as described in (A) and (B)above, good alignment of first-size and second-size documents in thedischarge direction can be maintained. In particular, good alignment ofthe first-size and second-size documents can be achieved even in thecase where the conveyance speed of documents is set to a value higherthan 340 mm/s, for example, 400 mm/s or higher, for improving theproductivity.

Further, in the present exemplary embodiment, the third projections 104are provided on the discharge tray 303 such that L2<L3 and H2<H3 aresatisfied. As a result of this, as described in (C) above, goodalignment of documents of the third size can be maintained in thedischarge direction in addition to the documents of the first size andthe second size.

To be noted, the third projections 104 serving as third supportingportions of the present exemplary embodiment have shapes projecting tohigher positions than upper surfaces 107 of the ribs extendingdownstream from the second projections 103 in the discharge direction.However, the third projections 104 may be omitted and surfaces 108 whichare extensions of the upper surfaces 107 and inclined upward toward thedownstream side in the discharge direction may be provided. Thesesurfaces 108 serve as third supporting portions that support the lowersurface of a third-size document at a position downstream of the secondvertices 601 in the discharge direction and higher than the secondvertices 601 in the gravity direction.

OTHER EMBODIMENTS

In the exemplary embodiment described above, the first projection 102,the second projections 103, and the third projections 104 are all formedas rib-like projections extending in the discharge direction. However,each supporting portion may be formed as a surface also extending in theY direction as long as the supporting portion functions as the firstsupporting portion, the second supporting portion, or the thirdsupporting portion. For example, a surface having the same outline asthe second projections 103 as viewed in the Y direction may be formed onthe entirety of the discharge tray 303 in the Y direction, and the firstprojection 102 may be formed to project from a predetermined position inthe Y direction on this surface. In addition, for example, a rib-likeprojection may be used instead of the upstream supporting surface 101having a planar shape as the upstream supporting portion to support asheet.

In addition, although the discharge tray 303 capable of supporting atleast three documents having different lengths in the dischargedirection has been described in the exemplary embodiment describedabove, as a matter of course, the discharge tray may be formed tosupport documents of a wider variety in size. For example, an extensiontray 109 housed in the discharge tray 303 may be pulled out to thedownstream side in the discharge direction in FIG. 1 such that adocument of a fourth size longer than the third size in the conveyancedirection can be supported. For example, the fourth size is an LGL sizehaving a length of 355.6 mm in the conveyance direction. In this case,the downstream end of the extension tray 109 having been pulled out inthe discharge direction is preferably higher than the third vertices 701of the third projections 104.

In addition, although a case where the technique of the presentdisclosure is applied to a sheet discharge configuration of an ADF hasbeen described in the exemplary embodiment described above, thetechnique of the present disclosure is also applicable to sheetdischarging apparatuses other than ADFs, for example, an apparatus thatdischarges a recording material on which an image has been alreadyformed by an image forming apparatus.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2019-102798, filed on May 31, 2019, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. A sheet discharging apparatus comprising: adischarge unit configured to discharge a sheet in a discharge direction;a stacking portion on which sheets discharged by the discharge unit arestacked; and a swing guide configured to swing about a swing shaft,wherein the stacking portion comprises: an upstream supporting portionconfigured to support a sheet discharged from the discharge unit; a wallsurface portion erecting upward from an upstream end of the upstreamsupporting portion in the discharge direction; a first supportingportion provided downstream of the upstream supporting portion in thedischarge direction and comprising a first inclined surface inclinedupward toward a downstream side in the discharge direction; a secondsupporting portion provided downstream of the upstream supportingportion in the discharge direction and comprising a second inclinedsurface inclined upward toward the downstream side in the dischargedirection; and a third supporting portion provided downstream of thefirst supporting portion and the second supporting portion in thedischarge direction and comprising a third inclined surface inclinedupward toward the downstream side in the discharge direction, whereinthe swing shaft is positioned above the first inclined surface, andwherein the swing guide is configured to overlap with the firstsupporting portion as viewed in a width direction of a sheetperpendicular to the discharge direction in a case where the swing guideis not in contact with a sheet discharged by the discharge unit, andswing in a case where the swing guide is pushed by a sheet, and wherein,as viewed in the width direction, the stacking portion is configured tosatisfy L1<L2, L4<L2, H1<H2, H4<H2, L2<L3, and H2<H3, where L1represents a distance from a first intersection point to a first vertexin a horizontal direction, the first intersection point being anintersection point where the wall surface portion and the upstreamsupporting portion intersect, the first vertex being a highest point ofthe first inclined surface in a gravity direction, H1 represents adistance from the first intersection point to the first vertex in thegravity direction, L2 represents a distance from the first intersectionpoint to a second vertex in a horizontal direction, the second vertexbeing a highest point of the second inclined surface in the gravitydirection, H2 represents a distance from the first intersection point tothe second vertex in the gravity direction, L3 represents a distancefrom the first intersection point to a third vertex in the horizontaldirection, the third vertex being a highest point of the third inclinedsurface in the gravity direction, H3 represents a distance from thefirst intersection point to the third vertex in the gravity direction,L4 represents a distance from the first intersection point to a secondintersection point in the horizontal direction, the second intersectionpoint being an intersection point where the swing guide and the firstinclined surface of the first supporting portion intersect, and H4represents a distance from the first intersection point to the secondintersection point in the gravity direction.
 2. The sheet dischargingapparatus according to claim 1, wherein, regarding L1 [mm], L2 [mm], andL3 [mm], 148≤L1<180, 180≤L2<240, and 240≤L3<360 are satisfied.
 3. Thesheet discharging apparatus according to claim 1, wherein, regarding H1[mm], H2 [mm], and H3 [mm], 20≤H1<40, 40≤H2<60, and 60≤H3<80 aresatisfied.
 4. The sheet discharging apparatus according to claim 1,wherein L1 is substantially equal to L4, and H1 is substantially equalto H4.
 5. The sheet discharging apparatus according to claim 1, wherein,as viewed in the width direction, an angle θ2 formed between thehorizontal direction and a straight line connecting a fourthintersection point and the first vertex is smaller than an angle θ1formed between the horizontal direction and a straight line connecting athird intersection point and the first vertex, the third intersectionpoint being an intersection point of the upstream supporting portion andthe first inclined surface, the fourth intersection point being anintersection point of the upstream supporting portion and the secondinclined surface.
 6. The sheet discharging apparatus according to claim5, wherein, regarding θ1° and θ2°, 40≤θ1≤55, 25≤θ2≤40, and θ1−θ2≥5 aresatisfied.
 7. The sheet discharging apparatus according to claim 1,wherein conveyance speed of a sheet by the discharge unit is higher than340 mm/s.
 8. The sheet discharging apparatus according to claim 1,wherein the swing guide includes a shape branched to a first side and asecond side in the width direction at a distal end portion farther fromthe swing shaft, and is configured such that, in a case where the swingguide is not in contact with a sheet discharged by the discharge unit,the first supporting portion is positioned between a branch to the firstside and a branch to the second side of the branched shape.
 9. The sheetdischarging apparatus according to claim 8, wherein the secondsupporting portion comprises a first projected portion positioned on thefirst side of the first supporting portion in the width direction andextending in the discharge direction, and a second projected portionpositioned on the second side of the first supporting portion in thewidth direction and extending in the discharge direction, and whereindistal ends of the branched shape of the swing guide are respectivelypositioned between the first supporting portion and the first projectedportion in the width direction and between the first supporting portionand the second projected portion in the width direction.
 10. A sheetdischarging apparatus comprising: a discharge unit configured todischarge a sheet in a discharge direction; a swing guide configured toswing about a swing shaft; a first supporting portion configured tosupport a sheet discharged from the discharge unit and comprising afirst inclined surface inclined upward toward a downstream side in thedischarge direction; a second supporting portion configured to supportthe sheet discharged from the discharge unit and comprising a secondinclined surface inclined upward toward the downstream side in thedischarge direction; a third supporting portion provided downstream ofthe first supporting portion and the second supporting portion in thedischarge direction and comprising a third inclined surface inclinedupward toward the downstream side in the discharge direction; and a wallsurface portion configured to contact with an upstream end of the sheetsupported by the first supporting portion in the discharge direction,wherein the swing shaft is positioned above the first inclined surface,wherein the swing guide overlaps with the first inclined surface of thefirst supporting portion as viewed in a width direction of a sheetperpendicular to the discharge direction in a case where the swing guideis not in contact with a sheet discharged by the discharge unit, whereinthe swing guide swings in a case where the swing guide is pushed by asheet, wherein a highest point of the second inclined surface isdownstream of a highest point of the first inclined surface in thedischarge direction, wherein the highest point of the second inclinedsurface is higher than the highest point of the first inclined surface,wherein a highest point of the third inclined surface is downstream ofthe highest point of the second inclined surface in the dischargedirection, and wherein the highest point of the third inclined surfaceis higher than the highest point of the second inclined surface.
 11. Animage reading apparatus comprising: an image reading unit configured toread image information from a sheet; a conveyance unit configured tofeed and convey a sheet toward a reading position of the image readingunit; and the sheet discharging apparatus according to claim 1configured to discharge a sheet having passed the reading position. 12.The image reading apparatus according to claim 11, further comprising afeed tray configured to support a sheet fed and conveyed by theconveyance unit, wherein the swing shaft of the swing guide is swingablysupported by the feed tray.
 13. An image forming apparatus comprising:the image reading apparatus according to claim 11, and an image formingunit configured to form an image on a sheet.
 14. A sheet dischargingapparatus comprising: a discharge unit configured to discharge a sheetin a discharge direction; a swing guide configured to swing about aswing shaft; and a stacking portion on which sheets discharged by thedischarge unit are stacked, the stacking portion comprising a firstportion provided with a first surface on an upper portion of the firstportion, wherein the first surface is configured to support the sheetand is inclined upward toward a downstream side in the dischargedirection, a second portion arranged apart from the first portion in asheet width direction perpendicular to the discharge direction andprovided with a second surface on an upper portion of the secondportion, wherein the second surface is configured to support the sheetand is inclined upward toward the downstream side in the dischargedirection, and a moving member provided movably in the dischargedirection with respect to the first portion and the second portion,wherein the moving member is configured to be in contact with the sheetdischarged by the discharge unit, is arranged between the first portionand the second portion in the sheet width direction, and can bepositioned at a position downstream of the first surface and the secondsurface in the discharge direction, wherein the swing shaft ispositioned above the first surface and the second surface, wherein theswing guide overlaps with the first portion and the second portion ofthe stacking portion as viewed in the sheet width direction in a casewhere the swing guide is not in contact with a sheet discharged by thedischarge unit, wherein the swing guide is configured to swing in a casewhere the swing guide is pushed by the sheet, and wherein the swingguide is arranged such that a lower end of the swing guide is not incontact with the stacking portion.
 15. The sheet discharging apparatusaccording to claim 14, wherein the stacking portion comprises a bottomsurface disposed between the first portion and the second portion in thesheet width direction, the bottom surface being lower than the firstportion and the second portion, wherein the first portion comprises afirst connecting surface connecting the bottom surface and the firstsurface, the first connecting surface extending in a gravity directionand in the discharge direction, wherein the second portion comprises asecond connecting surface connecting the bottom surface and the secondsurface, the second connecting surface extending in the gravitydirection and in the discharge direction, and wherein the swing guideand the moving member are arranged between the first connecting surfaceand the second connecting surface in the sheet width direction.
 16. Thesheet discharging apparatus according to claim 14, wherein the stackingportion comprises a projecting portion projected upward and configuredto support the sheet, wherein the projecting portion is arranged at aposition downstream of the first surface and the second surface in thedischarge direction, wherein a top of the projecting portion is abovethe first surface and the second surface, and wherein the projectingportion is arranged at a position in the sheet width direction differentfrom the moving member.
 17. The sheet discharging apparatus according toclaim 14, wherein the stacking portion comprises a projecting portionprojected upward and configured to support the sheet, wherein theprojecting portion is arranged at a position downstream of the firstsurface and the second surface in the discharge direction, wherein a topof the projecting portion is above the first surface and the secondsurface, and wherein the moving member is movable to a position where atleast a part of the moving member is higher than the projecting portion.18. An image reading apparatus comprising: a tray on which sheets to befed are stacked; an image reading unit configured to read imageinformation on the sheet fed from the tray; and the sheet dischargingapparatus according to claim 14 configured to discharge the sheet readby the image reading unit, wherein the swing guide is supported by thetray in a swingable manner.
 19. The sheet discharging apparatusaccording to claim 1, wherein the swing guide is arranged such that alower end of the swing guide is not in contact with the stackingportion.
 20. The sheet discharging apparatus according to claim 14,wherein the moving member is able to contact to the sheet supported bythe first surface and the second surface at a position downstream of thefirst portion the second portion in the discharge direction.